1. Field of the Invention
The present invention generally relates to an acceleration sensor and engine control arrangement for a motor vehicle. More particularly, the present invention relates to an acceleration sensor and controller configuration that controls engine operations depending upon a variety of sensed operational modes.
2. Description of the Related Art
Motorcycles generally comprise a frame with a steerable front wheel and a driven rear wheel. An engine is mounted within the frame between the front wheel and the back wheel. The engine generally comprises at least one piston that reciprocates within a bore formed in the cylinder block. A cylinder head, together with the cylinder bore and the piston, defines a combustion chamber in which an air-fuel mixture is compressed and ignited. A throttle valve may be provided to control the air flow rate into the combustion chamber and a fuel injection system may be provided to control the amount of fuel mixed with the air. An ignition system, including a spark plug, is provided for igniting the air-fuel mixture that is compressed within the combustion chamber by the piston. Ignition and burning of the air-fuel mixture drives the piston downward within the cylinder bore. A connecting rod transfers the reciprocating linear movement of the piston to a rotatable crankshaft.
A controller, such as an electronic control unit (“ECU”), communicates with various engine and motorcycle components. The ECU, in particular, generally controls timing of the ignition system and injection of the fuel injection system based upon data received from various sensors. For instance, in some motorcycles, the ECU receives information regarding the engine speed from an engine speed sensor, the throttle position from a throttle position sensor and engine temperature from a temperature sensor. Based upon this information, various maps are consulted to determine a desired ignition timing and a desired injection amount and timing.
In some arrangements, the engine is not an internal combustion engine. Rather, due to recent governmental regulations, electric vehicles are becoming more popular. The electric vehicles generally employ an ECU to help control output of at least one electric motor based, at least in part, upon operator demand. Nevertheless, an ECU is used to at least partially control motor operation.
Motorcycles generally require operation at a lean angle relative to vertical; the lean angle is used to assist in turning. Unfortunately, motorcycles occasionally tip over or are leaned too far during normal operation. Such tipping can result in fuel being spilled from the fuel supply system and can otherwise adversely affect engine operation. Accordingly, a system is desired that will deactivate the fuel supply system and possibly the engine during such tipping.
Additionally, motorcycles, like all vehicles, can become involved in accidents. During such accidents, the motorcycles are rapidly decelerated due to the impact forces. Such deceleration, again, can terminate in a fuel spill such as that discussed above or in adverse consequences for the engine. Thus, the system preferably can account for rapid deceleration that is indicative of a collision and desirably will deactivate the fuel supply system and possibly the engine in the event of such a collision.
Furthermore, due in part to the higher engine output to vehicle weight ratios, as well as vehicle body design, motorcycles have the ability to raise up on a rear driven wheel during rapid acceleration. This phenomenon often is referred to as a wheelie. Wheelies generally are undesirable because they cause the front steerable wheel to raise off of the ground, for instance. To date, anticipating or detecting such a phenomenon and reducing the likelihood or the length of the phenomenon, however, has been fairly difficult. Accordingly, a system is desired that can correct a wheelie through appropriate detection and correction techniques.
One other issue that desirably could be corrected is the wasting of electricity and the wasting of space when a motorcycle is provided with an alarm system or other theft deterrent device in addition to the basic ECU. While physical locks are functional, they require storage space or complicated mechanical structure. Thus, alarms are preferred from the standpoint of space and simplicity of design. One drawback to alarm systems, however, is the proliferation of electrical components required for such alarm systems and the consequent difficulty in manufacturing an OEM-optional alarm device. In other words, motorcycle manufacturers need to reduce the number of variations in base components, such as circuit boards. Providing an alarm system as an option has heretofore been undesirable due to the need to provide different circuitry for alarm-equipped motorcycles and for non-alarm-equipped motorcycles, respectively. As an alternative, the circuitry could be designed with most of the components necessary for the alarm already present and active on the circuit but the alarm device and other related components not present. This is undesirable, however, because of the increased power consumption that would result. Accordingly, a simple but energy efficient alarm option is desired.